More Republican seats could become legitimate takeover targets for Democrats in reaction to a polarizing and unpopular President Donald Trump, Nathan L. Gonzales writes. (Bill Clark/CQ Roll Call)

Republican gerrymandering has put the House majority out of reach for Democrats, we’re told. But even though the initial playing field of competitive races is probably too small for the GOP to fall into the minority, Republicans shouldn’t get too comfortable. The playing field could expand dramatically over the next 20 months.

John Rogers was part of the National Republican Congressional Committee team that limited the party’s losses in the House to a net of just six seats in last year’s election. (Tom Williams/CQ Roll Call file photo)

Midterm elections are supposed to be trouble for the president’s party, but House Republicans are confident that if they have a problem, John Rogers can solve it.

Rogers was born in Amsterdam, New York, a small-town about a half-hour west of Albany, but Republican friends know him best for once identifying an unlikely takeover opportunity three hours south in New York City.

When nearly 90 percent of the batch of House ratings changes are in your favor, it’s normally great news. But with a limited House playing field, Democrats need to win virtually all of the competitive seats, and some initial takeover targets look like they are slipping out of reach.

The good news for Republicans is that the bottom hasn’t fallen out from underneath their down-ballot candidates. The bad news is that there are still nearly three weeks left before Election Day, and 24 hours in each day for Donald Trump to torpedo the party’s chances of holding the House.

District-level polling after the release of the 2005 “Access Hollywood” video and the second debate between Trump and Hillary Clinton showed some vulnerability for Republicans, particularly in suburban districts. But we didn’t see a widespread cratering of GOP candidates in the competitive districts or evidence that the number of competitive seats is increasing dramatically.

Missouri Sen. Roy Blunt has been on a steep slide in his race against Democratic Secretary of State Jason Kander in the Show Me State. (Bill Clark/CQ Roll Call file photo)

With three weeks to go before Election Day, the fight for control of the Senate is coming down to six states hosting very close contests.

New Hampshire, Nevada, and Pennsylvania have been tossup races for months and are now joined by Missouri and Indiana. Republican Sen. Richard M. Burr’s re-election race in North Carolina is rated as Tilts Republican for now, but may end up in the same category.